Electric oven.



J. V onown ELECTRIC OVEN.

APPLICATION I ILED NOV. 29, 1909.

985,144. Patented Feb. 28, 1911.

UNITED STATES PATENT OFFICE.

JAMES v. CHOWN, on OAKLAND, cALIFonNiA, ASSIGNOR OF ONE-SIXTH 'ro R.PORTER GILES, ONE-SIXTH T0 WILLIAM s. COX, onn-srx'rnc T0 J. CLEM AnY,AND ONE-HALF T0 JESSIE MARIAN cnown, ALL on OAKLAND, CALIFORNIA.

ELECTRIC o vnn.

Specification of Letters Patent. Application filed November'29, 1909.Serial No. 530,331.

Patented Feb. 28, 1911.

My invention relates to electric ovens or.

heating chambers wherein the heat used for cooking or other purposes isgenerated through the medium of suitable electrical resistance.

The object of the invention is to provide a simple, cheap,economically-operateel,

' practical oven, particularly designed for household purposes to takethe place of the ordinary gas stove or oven which is so injurious tohealth, and in which oven or heating vessel I employ a latentheat-holder or retainer into which the heat is absorbed as the oven isgradually heated up; suitably insulating this latent heat-holder fromthe outside atmosphere so that after a suiiicient heat is obtained inthe oven a part of the .current may be cut off, and a sufficient cookingheat will be maintained through the remaining small current used, andthe reserve supply of heat stored in the latent heat holder, and whichis gradually returned to the oven.

The invention consists of the parts and the construction and combinationof parts as hereinafter more fully: described and claimed, havingreference to the accompanying drawings, in which Figure 1 is alongitudinal section of the invention. Fig. 2 1s a plan view of thesame.

My oven, as actually constructed and successfully used, consists of anoutside wall A of suitable material, such as diatomaceous earth,carbonate of magnesia, or other non conductor of heat. I prefer to usediatomaceous earth, or a mixture of diato'maeeous earth,.;sawdust andlime, since experience shows that this is an exceedingly good heatinsulator. These walls A are of suitable thickness to'su'ccessfull yprevent the radiation of any heat enei'ated within the bakin chamber 2.T is oven is preferably pro vi ed with a door 3 of the same material asthe walls A, and the door may be hinged at one side and made with stepjoints, as shown, ,so that when. the door is closed practically tainedwithin the oven. Both the walls A all the heat generated by the coil 4:Will be re andthe door 3 of the oven-are lined on the inside, as shownat 5, with a suitablelatent heat-holder, such as soapstone or fire-clay,

either of which has the quality of absorb ing the heat, This lining 5 isin marked contrast to the outside insulating wall A, and the distinctionis one to be carefully borne in mind. The outside shell A prevents theheat from passing beyond the heat absorbing and retaining lining 5, sothat if the-heat in the coil 4L is cut off orreduced and the ovenallowed gradually to cool, the heat stored in the lining will be givenbackinto the oven, rather than allowed to escape to the outer atmosphereand be lost. Preferably the lining 5 is covered on the inside of theoven by a metal shell 6 which is in the nature, more or less, of a goodconductor of heat and does not interfere with the return radiatingaction of the .heat stored in lining 5 back into the oven.

Any suitable form of electrical heater 4 may be employed, and theinterior of the oven may be provided with removable shelves 7 and ribs 8for the support of such shelves.

The metal lining is preferred, as it keeps the odors generated withinthe cooking chamber from penetrating, into the more or less-absorbentlining 5, and makes the oven easy to clean.

If desired, a thermometer 9 may be attached to the ovendoor, so as toindicate to the operator the temperature of the oven chamber 2.

In order to give stability to the structure and prevent the compositionof the oven walls being broken or injured, I employ in practice askeleton frame-work of iron or wood, and represented in the drawings bythe corner pieces 10 anddiagonal pieces 11.

In practical operation, the article or articles to be cooked are putinto the oven,

chamber and the door 3 securely. closed.

Preferably the coil 4 is connected with a suitable electricalcontrolling device, as the rheostai'. 100, whereby when the heat isfirst.

turned onthe full curTent will be allowed to pass through the coils, soas quickly to heat up the oven chamber. When the temperature of the ovenchamber has been raised sufficiently and the absorptive lining 5 highlyheated, the rheostat can be turned so -as to regulate the strength ofthe current through all of the coils a reduced current, whensupplemented by the reserve supply of heat stored in the latentheat-holding lining'f), being sufiicient to maintain the oven at aproper temperature.

It is understood that the sides, ends, and top and bottom of the ovenchamber are surrounded by this latent heat-holder 5 in the outsideinsulating shell A.

Having tlius' described my invention, what I claim and desire to secureby Letters Patent is-/ An elec 'ric oven comprising a shell embodyingannixture of diatomaoeous earth,

Gopies of this patent may be obtained sawdust and lime, and having itsinterior lined with a coating of fire-clay, sn id composition and lininginclosing an oven chamber, a door of like composite material similarlylined closing said oven chamber, an electric heating coil for the oven,with means for regulating the amount of heat from the outside' Intestimony whereof I have hereunto set my hand .in the presence of twosubscribing witnesses.

JAMES V. CHOWN.

Witnesses:

RAYMOND A. LEONARD, CHARLES EDELMAN.

